Expression of thymosin beta4 during chick development.

We cloned the chick homologue of Homo sapiens thymosin beta4, encoding a G-actin sequestering factor which plays an important role in angiogenesis, cell motility and tumorigenesis. The thymosin beta4 gene is highly conserved between chick and human. Its expression was analyzed during different stages of development. At early stages thymosin beta4 is expressed in the mesoderm and endoderm and in Hensen's node. Later, thymosin beta4 transcripts are found in the head mesenchyme, somites, dorsal root ganglia, neural tube, brain, blood vessels and feather buds. The pattern of thymosin beta4 expression in blood vessels indicates a function mainly in development of the blood circulatory system which closely parallels findings in vitro. The observed expression pattern shows a high similarity to expression data published for mice, mainly in the heart and in the nervous system. Important new aspects are the early onset of expression, the expression in the mesoderm preceding heart formation and the involvement in feather development.

Expression of kinesin kif5c during chick development.

Kinesins are molecular motors associated with microtubules. They act mainly as intracellular transport proteins carrying different cargos like organelles along the microtubules. We cloned the avian homologue of the mammalian kif5c gene, a member of the khc family coding for the heavy chain of conventional kinesin. Its murine homologue has been described to be specific for neuronal tissue. Here we present the expression pattern of kif5c in chick embryos. We found a highly dynamic expression pattern for kif5c in a variety of developing tissues including neuronal and mesodermal tissues. In young embryos the expression pattern around Hensen's node is asymmetric with stronger expression on the right side, implying that kif5c is involved in the formation of the left-right body axis. A connection with intracellular transport linked to early asymmetric morphogenesis in the node is likely. Vesicles containing signaling molecules could be possible cargos. At later stages, kif5c expression is found in the paraxial, intermediate and somatic mesoderm and in the tail bud. The expression in the paraxial mesoderm occurs first during segmentation and continues in the epithelial somites and the dermomyotome. During neurulation kif5c is expressed in ectodermal and neural-plate cells. In older embryos, the expression is restricted to the dorsal root and cranial ganglia, neural tube and olfactory tract. Taken together, our results demonstrate that in the chick embryo, kif5c plays a role during different morphogenetic processes.

Rutkow PerFix-plug repair for primary and recurrent inguinal hernias--a prospective study.

Surgery of the groin hernia has become more a question of the applied tension-free, mesh technique. Whereas studies on laparascopic versus open tension-free hernia repair or open-mesh versus open-nonmesh repair have been performed sufficiently, data regarding the open tension-free plug-and-patch technique are rather poor. During the period from January 2001 to October 2003, we followed and filed 766 hernia repairs in the plug-and-patch technique of Rutkow. Follow up was during the hospital stay, 4 weeks, and minimally 12 months after operation. The main follow-up variables were complications, recurrence rate, and pain. The mean operating time was 37.8 +/- 15.85 (12-135) minutes. In 141 (19.3%) patients (n=730), the ilioinguinal nerve was resected. The 1 intraoperative complication that occurred was a severed small intestine. Length of hospital stay was 2.09 +/- 1.35 (0-17) days, work leave lasted for 15.3 +/- 12.42 (0-60) days, and return to normal daily activities was possible within 6.54 +/- 6.86 (0-35) days. Twenty-two (2.9%) patients (n=766) developed a postoperative hematoma as the most common complication, and a reoperation was required 17 (2.2%) times during the hospital stay. Early complications included hematoma (3.7%), seroma (3.5%), infection (0.2%), necrosis of 1 testicle (0.2%), persisting scrotal swelling (1.5%), persisting pain (0.9%), and hypoesthesia (2.4%). Within 4 weeks, 4 (0.9%) patients were reoperated for 1 seroma, hematoma, infection, and testicle necrosis. After 605.4 +/- 154.5 (365-1018) days, the following 19 (5.7%) patient complaints were noted: persisting pain (2.1%), hypoesthesia (1.8%), foreign-body feeling (0.6%), scrotal swelling (0.6%), and 1 (0.3%) mesh dislocation. Six (1.8%) reoperations have been performed. The overall recurrence rate was 1.8% (n=6), for primary 1.5% (n=4), and 3.3% (n=2) for recurrent hernias; 96.3% of the patients would agree to undergo the same operation a second time. Tension-free repair of the inguinal hernia by the plug-and-patch technique is a quick and secure method that simplifies hernia surgery without compromising the high-quality standards such as a low recurrence rate and low pain load of the patient. Patients had a fast recovery with a subsequent short work leave. The method is a simple, effective, and economical operation, suitable as a standard performed in local anesthesia on an out-patient basis.

SF/HGF is a mediator between limb patterning and muscle development.

Scatter factor/hepatocyte growth factor (SF/HGF) is known to be involved in the detachment of myogenic precursor cells from the lateral dermomyotomes and their subsequent migration into the newly formed limb buds. As yet, however, nothing has been known about the role of the persistent expression of SF/HGF in the limb bud mesenchyme during later stages of limb bud development. To test for a potential role of SF/HGF in early limb muscle patterning, we examined the regulation of SF/HGF expression in the limb bud as well as the influence of SF/HGF on direction control of myogenic precursor cells in limb bud mesenchyme. We demonstrate that SF/HGF expression is controlled by signals involved in limb bud patterning. In the absence of an apical ectodermal ridge (AER), no expression of SF/HGF in the limb bud is observed. However, FGF-2 application can rescue SF/HGF expression. Excision of the zone of polarizing activity (ZPA) results in ectopic and enhanced SF/HGF expression in the posterior limb bud mesenchyme. We could identify BMP-2 as a potential inhibitor of SF/HGF expression in the posterior limb bud mesenchyme. We further demonstrate that ZPA excision results in a shift of Pax-3-positive cells towards the posterior limb bud mesenchyme, indicating a role of the ZPA in positioning of the premuscle masses. Moreover, we present evidence that, in the limb bud mesenchyme, SF/HGF increases the motility of myogenic precursor cells and has a role in maintaining their undifferentiated state during migration. We present a model for a crucial role of SF/HGF during migration and early patterning of muscle precursor cells in the vertebrate limb.